Organisms living in aquatic ecosystems may experience high doses of natural UV radiation. UV radiation penetrates the water column down to several meters. The penetration depth differs depending on the contents of particles, dissolved matter or pollutants. The aim of this study was to establish the dose-response relationship of phenotypic changes caused by UV.

Pelagic embryos of fish may be exposed to high doses of natural UV radiation. Shortwave UV, UVB, as well as UVA may penetrate the water column to depths of several meters. The penetration depth differs depending on the contents of particles, dissolved matter or pollutants. Pollutants may also interact photochemically with UV- and visible radiation.